The Shrinking Value of the Dollar

The CPI inflation calculator uses the average Consumer Price Index for
a given calendar year. This data represents changes in prices of all goods
and services purchased for consumption by urban households. This index
value has been calculated every year since 1913. For the current year, the
latest monthly index value is used. In 2008, for example, it took $21.57
to buy what $1 bought in 1913. Note that in 1920, it cost $2.02, and
declined in 1925 and through the 1930s, illustrating the effect of the
Great Depression, when prices slumped. Prices did not pass $2 again until
1950.